ms34.c

#include<stdio.h>

int f(int n,int k)
{
if (n==0)
return 0;
else
 if(n%2)
 return f(n/2,2*k)+k;
 else return f(n/2,2*k)-k;
}
int main()
{

printf("\n %d",f(20,1));

}